Heating and cooling system



March 5, 1968 H. LEONARD, JR 3,371,706

HEATING AND COOLING SYSTEM Original Filed June 23, 1964 2 Sheets-Sheet 1 INVENTOR. LOUIS H. LEONARD, JR.-

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ATTORNEY.

March 5, 1968 L. H. LEONARD, JR 3,371,706

HEATING AND COOLING SYSTEM Original Filed June 23, 1964 2 Sheets-Sheet 8 ATTORNEY.

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2 5 a 62 vi United States Patent 3,371,706 HEATENG AND COOLING SYSTEM Louis H. Leonard, In, De Witt, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Original application June 23, 1964, Ser. No. 377,319, now Patent No. 3,288,203, dated Nov. 29, 1966. Divided and this application Aug. 29, 1%6, Ser. No. 575,773

7 Claims. (Cl. 1651) ABSTRACT OF THE DISCLOSURE Method of operating a heating system of a steam condenser in which the capacity of the system is regulated by passing a noncondensible vapor into the steam condenser.

This application is a division of my copending application Ser. No. 377,319, filed June 23, 1964, now Patent No. 3,288,203 granted Nov. 29, 1966, and relates broadly to heating and cooling systems. More particularly, this invention relates to a capacity control for a heating and cooling system.

Various types of refrigeration systems, such as absorption systems and refrigerant compressor systems, are well known in the art. The contruction, components and relative association of the components, as well as the operating characteristics of such systems are also well known.

However, each system has certain disadvantages as well as particular advantages, but attempts to provide systems combining the dvantages of accepted systems while avoiding their disadvantages have generally resulted in systems which were impractical.

For example, various expedients are known in the art for automatically controlling the capacity of the various systems. In systems utilizing a refrigerant compressor, such control is usually accomplished by varying the compressor speed or adjusting guide vanes in the compressor inlet to regulate the flow of refrigerant. Guide vane installations are expensive and generally require involved actuating mechanism. In systems which provide capacity control by regulating the compressor speed, this is commonly accomplished by controlling the speed of the compressor drive means, such as a steam turbine. Turbine speed control is generally obtained by varying the pressure of steam supplied to the turbine and this is usually accomplished either by varying the heat input to a steam generator or by adjusting a steam pressure regulating valve in the line between the steam generator and the turbine. Regulating the heat input to the steam generator usually results in poor capacity control because an inherently slow response of the steam generator causes the speed change of the turbine to lag behind the control signal varying the heat input to the steam generator, resulting in slowchange in the capacity of the system. When a steam pressure regulating valve is used, a significant pressure drop exists across the valve and this may result in an unnecessarily high steam rate, particularly at low steam pressures,-producing higher operating costs. Furthermore, suitable steam pressure regulating valves are expensive and often require complicated and expensive electrical and mechanical actuating controls which increase the cost of the system. Another consideration is that of inherent instability of prior refrigeration system controls in that large, almost instantaneous changes in the operation of the system may occur for a variety of reasons, as is understood in the art.

Refrigeration systems which utilize a high speed centrifugal compressor and a relatively high molecular weight refrigerant are .known to possess many theoretical advantages in size, cost and efliciency, as is more fully ice discussed in my prior copending US. patent application, Ser. No. 112,679, filed May 25, 1961, for a Method and Apparatus for Heating and Cooling. However, practical problems affect the life and reliability of many such systems, and these problems have greatly increased the cost and complexity of the systems, so that earlysystems of this type have received littlegeneral acceptance. 7

In three-pipe air conditioning installations, both cooling water and heating water are piped throughout the installation so that air circulating within the various areas can be regulated independently to a desired temperature. As is generally understood, when the cooling demand throughout the installation is high, the cooling capacity of the system should greatly exceed the heating capacity, and under reverse conditions, the heating capacity should greatly exceed the cooling capacity of the system. To vary the heating and cooling capacities of a system inversely of each other, as is desirable in a typical three-pipe system, has required complicated and expensive controls and many machines used for simultaneous heating and cooling are too delicate and easily become inoperative should leakage occur. Furthermore, prior machines havev generally been unable to etficiently provide high heating capacity at low or Zero cooling capacity while maintaining the system in normal cooling operation.

A' primary object of this invention is to provide a new and improved heating and cooling system and method of providing heating and cooling.

It is an important object of this invention to provide a new and improved capacity control system in heating and cooling apparatus. A related object is to provide such a" control in apparatus incorporating a steam driven refrigeration system. Another related object is provision of such control by a regulated blanketing of a condensing, portion of a steam condenser employed in conjunction with the steam driven refrigeration system to suppress the condensing rate of steam discharged into the condenser. Another related object is provision for separating noncondensible vapor and steam mixed in the steam con-' denser, and returning the separated fluids for reuse in the system.

A further object is provision of a 'new and improved control system in a heating and cooling system for providing a stable system the normal operation of which changes slowly. A related object is provision of such" control wherein the heating capacity varies inversely of the cooling capacity.

A still further object is provision of a new and improved heat exchanger. A related object is provision of such a heat exchanger for condensing a fluid, such as steam, in a system for providing heating and cooling. Another related object is provision of such a heat exchanger in the form of a steam condenser. Another related object is provision of a new and improved method of controlling the condensing rate of a condenser. Still another related object is provision for controlled blanketing of a condensing portion of such a heat exchanger with a noncondensible vapor, preferably refrigerant vapor, to regulate the heating and condensing capacity of the heat exchanger, Stillanother related object is to provide an inexhaustable supply of the noncondensible vapor by recirculating the refrigerant providing the vapor. Another related object is provision of such a heat exchanger and method wherein a first condensing portion is blanketed with a noncon-' densi'ble vapor and a second condensing portion is main providing simultaneous heating and cooling utilizing the improved refrigeration system. A related object is provision therein for varying the heating capacity inversely of 3 the cooling capacity. Another related object is provision for extending the useful ranges of heating and cooling capacity. Still another related object is provision of such a system and method which is particularly suited for use in a three-pipe heating and cooling system.

A still further object is provision in a heating and cooling systemof a new and improved method for controlling heating capacity inversely of cooling capacity.

These and other objects of the invention will be apparent from the following description and the accompanying drawings in which:

FIGURE 1 is a flow diagram of a heating and cooling system, and illustrates certain control features of the system;

FIGURE 2 is a broken, longitudinal side view of a condenser unit including a steam condenser of this invention, with parts broken away for clearer illustration;

FIGURE 3 is a vertical sectional view of the condenser unit taken generally along the line III-III in FIGURE 2; and

FIGURE 4 is an end view from the right of the unit shown in FIGURE 2, with parts removed for clearer illustration.

The invention is illustrated in the form of apparatus, including a refrigeration apparatus for providing cooling, heating and simultaneous heating and cooling. The system is preferably airtight and may be considered as having a power side including a circuit for the circulation of a power fluid, and a refrigerant side including a circuit for the flow of a refrigerant fluid under the influence of drive means on the power side driven by the power fluid, with the operation of the apparatus regulated by a control system.

The invention will be described with reference to a preferred power fluid, which is water, and a preferred refrigerant which is octafluorocyclobutane, commonly referred to as C318 and having a chemical formula C 1 These fluids are particularly preferred because of their relative immiscibility and because they are inherently highly stable and do not tend to decompose or chemically react with each other or other materials in the system, or cause or promote corrosion and undesirable by-products. Also, this refrigerant is a relatively noncondensible vapor at the temperatures and pressure at which the power fluid (water) condenses as well as at the usual ambient atmospheric conditions of temperature and pressure. However, other power fluids and refrigerants having the desired chemical and physical properties may be utilized within the scope of this invention.

As illustrated in FIGURE 1, the power side includes a suitable steam generator 12 and a turbocompressor 13 including a turbine 14 which receives steam from the steam generator 12 and discharges exhaust steam to a steam condenser 16 here shown as part of a composite condensing unit as described in copending patent application Ser. No. 377,261, filed June 23, 1964, of Joseph Embury for a Heat Exchanger Unit. A steam condensate pump 17 returns the steam condensate from the steam condenser 16 to the steam generator 12 for recirculation through the power side, of the system. The turbocompressor 13 has water lubricated bearings, as 18, and the steam condensate pump 17 forwards steam condensate through a lubricant line 18' including a lubricant cooling heat exchanger 19, for lubricating the bearings 18.

The refrigerant side of the system includes a refrigerant compressor 20 of the turbocompressor 13. The compressor 20 is drivingly connected with the turbine 14 for passing compressed refrigerant vapor to a refrigerant condenser 21 'here shown as part of composite condensing unit, although a separate structure may be employed if desired to condense the refrigerant. Condensed refrigerant passes from the refrigerant condenser 21 to a refrigerant subcooler 22 and through a suitable refrigerant flow restricting means 23 into an evaporator or cooler 24, from which the refrigerant vapor is withdrawn by the refrigerant compressor 20, thus completing the refrigerant circuit of the system. A chilled water line 25 extends into the cooler and carries a heat exchange medium here in the form of chilled water, which is cooled by the refrigerant and circulated by means of a chilled water pump 26 to an area having a cooling requirement. The cooling capacity of the system varies in proportion to the compressor output.

A cooling tower or condensing water pump 27 circulates tower water through an inlet line 28 to the refrigerant subcooler 22 and into the refrigerant condenser 21 and then the steam condenser 16 and back to the tower through an outlet line 29. A branch line 30 in the condensing water inlet line 28 provides tower water to the lubricant water cooler 19 for cooling the lubricant water, and this branch terminates in the return line 29 to the tower. In general, control of condensing water temperature and flow rate is unnecessary, thus effectively minimizing scaling of condensing surfaces in the condensers.

The control system regulates the cooling and heating capacities of the refrigeration system by varying the steam condenser pressure as determined by the condensing rate of steam discharged into the steam condenser.

In my copending US. patent application, Ser. No. 377,313, filed June 23, 1964, for a Refrigeration System, cooling capacity control of the present system is more fully described. In brief, the condensing rate of the steam condenser is regulated by controlled blanketing of a first condensing portion or tube bundled 34 (which receives the tower water from the refrigerant condenser) with a noncondensible vapor, herein refrigerant vapor, introduced through a refrigerant line 34' from the cooler 24.

The quantity of noncondensible vapor effectively blanketing the first condensing portion 34 of the steam condenser is regulated by a modulating refrigerant valve 35 in the line 34'. The valve 35 is actuated responsive to chilled water temperature by means of a temperature sensor 37 on the chilled water line 25 so that as the cooling load drops more refrigerant vapor is introduced into the steam condenser 16 thus reducing the steam condensing rate to increase the steam condenser pressure,

and therefore the temperature of the saturated steam and the turbine discharge pressure to reduce the turbocompressor output and in general speed. The refrigerant is preferably withdrawn from the steam condenser at a constant rate, and herein a water supply pump 38 circulates impeller water for operating a jet pump 39 which withdraws the noncondensible vapor from the steam condenser 16 through a purge line 40 opening into the throat of the jet pump. Impeller water temperature is maintained below the saturation temperature of water in the steam condenser to prevent water from flashing in the jet pump 39, and to this end, the hot vapors withdrawn from the steam condenser are cooled in the cooler 24. The water supply pump 38 further provides make-up water for the steam generator 12 through a makeup water line 40' to the steam condenser 16.

Simultaneous heating and cooling, wherein the heating and cooling capacities of the system vary inversely of each other, is provided. A second condensing portion or tube bundle 41 in the steam condenser is maintained effectively free of blanketing by refrigerant vapor in the steam condenser to maintain its full condensing capacity and maximum heating of a heat exchange medium, herein water, circulated through the bundle 41 and to a load to be heated by means of a heating water pump 41 in a heating line 41" to the area having a heating requirement. Thus, at high cooling capacity only a small quantity of refrigerant is in the steam condenser to blanket the first condensing portion 34 and the condensing rate is high so that the steam condenser pressure is low and the temperature of saturated steam in the condenser is correspondingly low. Therefore, the temperature of the water in the second condensing portion 41 is low and little heat is provided for the load to be heated. Conversely, when the cooling capacity is low the heating capacity is high, and the temperature of the heating water is at high, useable temperatures.

A hot gas bypass for increasing the heating capacity of the system at low cooling capacity, agitating the refrigerant entering the cooler to provide improved heat transfer to the chilled Water line at low cooling capacity, and for effectively preventing compressor surge, includes a hot gas bypass line 42 for passing refrigerant gas from the refrigerant condenser 21 to the cooler 24. Operation of the bypass is controlled by a self-contained modulating refrigerant valve 42 which is operated responsive to steam condenser condition and, more particularly, by steam condenser pressure as determined by a valve pressure sensor 42 in the steam condenser 16. Alternatively, the valve 42 may be controlled responsive to steam condenser or turbine discharge steam temperatures which are equivalent to steam condenser pressure in view of existing saturated steam condition. Blanketing of the steam condenser first tube bundle 34 with refrigerant vapor can be expected to provide partial load operation down to about 50% of nominal full load cooling capacity. Without the hot gas bypass, the compressor would then go into surge and the machine would have to be shut down. As the compressor approaches surge condition, the heating capacity will increase in inverse proportion to the cooling capacity. By using the hot gas bypass for eifectively preventing compressor surge, substantially zero cooling capacity can be provided and the heating capacity increased simultaneously to about 75% of the nominal maximum winter heating capacity of the machine, and at useable heating water temperature levels. As the hot gas bypass 42 loads the compressor 20, the turbine 14 utilizes a greater quantity of steam to drive the compressor. Upon fully opening the hot gas bypass valve the compressor is loaded to the extent that no useful cooling is provided by the cooler 24. While the steam condenser pressure rises slightly because of the greater volume of entering steam during such loading, and therefore the temperature of the entering steam rises only slightly, the increased volume of steam provides a substantially increased source of heat for heating the second tube bundle 41, thereby increasing the heating capacity of the heating and cooling system. Thus, the suitability .of the machine for operation in conjunction with three-pipe systems is greatly enhanced.

To provide cooling without heating, the heating water pump 41' may be turned off. It should be noted that all pumps are preferably self-lubricated by water being pumped therethrough.

If it is desired to provide only heating, as for winter heating, the condensing water pump 2'7 may be shut oif and valve means 43 in the steam line to the turbocompressor 13 may be adjusted so that the steam bypases the turbine 14 and is injected directly into the steam condenser 16 for heating the second condensing portion 41. A heat exchanger 43 may be provided for cooling the jet impeller water circulated by the pump 38, to maintain the impeller water below the saturation temperature of water in the steam condenser to prevent water from flashing in the jet pump and rendering the purge inoperative.

In the illustrated apparatus the steam generator 12 supplies steam at a substantially constant presure p.s.i.g., for example) as controller for example, by a constant pressure regulating valve 50 in a steam supply line 51 to the turbine and including the valve means 43. By merely changing the internal design of the steam turbine section of the turbocompressor, the machine may be operated with any normally desired steam pressure.

As is more fully decribed in my copending US. patent application Ser. No. 377,258, filed June 23, 1964, for a Heating and Cooling Sytem, steam drives a turbocompressor rotor assembly 55 which is rotatably mounted in the turbocompressor housing 56 by means of the water lubricated bearings 18. From the bearings 18 the lubricating'water passes into a chamber 73 generally in the center of the housing 55. Suitable shaft seals, as 75, one at either end .of the portion of the housing 56 mounting the shaft, minimize leakage of steam and refrigerant between the turbine and the compressor and any leakagev passes into the chamber 73 from which the lubricating water and leakage pass through a drain line 76 to the steam condenser 16.

With particular reference to FIGURES 2-4, after passing the turbine rotor, the steam is saturated and passes through a turbine steam discharge passage 81 and into the steam condenser 16. More particularly, with reference to FIGURE 2, the turbocompressor 13 is suitably mounted on an end plate 82 of the steam condenser, as by bolts, with the turbine dischar e passage in communication with a steam inlet port 84 in the end plate. A condensate chamber 86 of the steam condenser 16 is in communication with the interior of a cylindrical shell 87 of the steam condenser 16 through a port 88 in the end wall plate 82. The turbocompressor drain 76 opens into the condensate chamber 86. The steam condensate pump 17 withdraws the steam condensate from the condensate chamber through a condensate line 103 and pumps the condensate back to the steam generator 12. Thus, the turbocompressor chamber 73, the steam discharge passage 81, the drain 76, and the interior of the steam condenser 16, are all at substantially the same pressure, that is, the steam condenser pressure which is below ambient atmospheric pressure during normal operation.

Within the steam condenser shell 87, both the first condensing bundle 34 and the second condensing bundle 41 may be of any suitable type such as straight through tubes, or as illustrated, U-tubes secured in and open through a header plate 101 opposite the end plate 82. A header chamber shell 102 is suitably secured to the header plate 101, as bybolts 1132 and has partitions, as 102", for circulating condensing water from the refrigerant condenser through the U-tubes of the first condensing portion 34 and then discharging the condensing water through the condensing water outlet line 2? to the cooling tower. Inlet and outlet branches of the heating water line 41 open into the header 102 and suitable communication is provided by means of the shell partitions 102" with the U-tubes of the second condensing portion 41 to provide water for condensing steam and for returning the heated water to the area having a heating requirement.

The refrigerant injected into the steam condenser to.

blanket the first condensing portion 34 enters the steam condenser through a refrigerant port 106 at the end of the refrigerant line 34' within the steam condenser 16 between the first condensing tube bundle 34 and the second condensing tube bundle 41 adjacent an end of the condensing tubes opposite the condensate port 88 and the steam inlet 84, as may best be seen in FIGURE 2.

A baffie 107(FIGURES 1-3) extends between upper and lower portions of the steam condenser between the first and second condensing tube bundles 34 and 41, to define a condensate section and another section, respectively, and to prevent the flow of fluids therebetween except in a limited area of communication 103 at the refrig-v erant port 106. The entering steam "first flows from the steam condenser inlet port 84 across the second condensing bundle 41 and then through the area of limited communication 108 between the upper and lower sections of the earn condenser and past the refrigerant inlet port 106, and then past the first condensing bundle 34-. The refrigerant vapor entering the steam condenser is is drawn across the tubes of the first condensing bundle 34, and in the illustrated embodiment each tube is efiectively individually enveloped by a sheath or layer of refrigerant vapor thereby insulating the tubes of the first condensing bundle from the steam to reduce the steam condensing capacity and the system cooling capacity while raising the pressure and temperature of the saturated steam in the condenser 7 to raise the systems heating capacity by providing more heat for rejection by bundle 41.

With reference to FIGURES 2 and 4, the purge line 40 opens into a side of the steam condensate chamber 86 at a level to withdraw steam condensate from the chamber should the condensate level rise too high. Responsive to a low condensate level in the condensate chamber 86, a float actuated sensor 112 opens a normally closed shut-off valve 113 in the make-up water line 40' from the water supply pump 38, to maintain a minimum level of condensate in the chamber 86.

In the illustrated embodiment, a cylindrical refrigerant condenser shell 116 extends between the condenser end plate 82 and the header plate 101 and envelopes the steam condenser shell 87 for effectively preventing leakage of air into the steam condenser and to insulate the steam condenser for winter heating, Suitable U-tubes, as 117, are provided in the refrigerant condenser and have adjacent ends suitably mounted in and opening through the header plate 101 in communication with partitioned areas of the header chamber shell 102 so that condensing water from the refrigerant subcooler 22 is first circulated through the refrigerant condenser U-tubes 117 and then passed through the tubes of the steam condenser first condensing bundle 34 before being discharged from the condensing unit through the condensing water outlet 29.

Responsive to the compressor 20 being driven by the turbine 14, refrigerant vapor is withdrawn from the cooler 24 through a suction line 121 to the compressor inlet, compressed, and discharged through a compressor outlet and a discharge line 122 into the refrigerant condenser 21 where it is condensed and cooled. The refrigerant condensate then flows through a refrigerant condensate line 123 into the refrigerant subcooler 22 from which it passes through the refrigerant flow restricting means 23, here in the form of a float valve unit, and flows through a cooler refrigerant supply line 124 and into a cooler refrigerant inlet 125 extending through a shell 126 of the cooler 24. A suitable equalizer line 126 connects the float valve unit chamber and the refrigerant condenser, for reasons well understood in the art.

The refrigerant inlet 125 opens into a refrigerant pan 127 spaced above the bottom of the cooler shell 126. A U-tube bundle 128 of the chilled water line 25 is within the refrigerant pan 127 so that during normal cooling operation of the system, the tubes are flooded by boiling refrigerant. As the refrigerant evaporates, the vapor passes into a refrigerant chamber 129 in an upper portion of the cooler shell 126 above the pan and the remaining liquid refrigerant is cooled thereby. A refrigerant outlet 130 opens into an upper portion of the refrigerant chamber 129 and is connected with the compressor inlet 120 by the suction line 121. The portion of the cooler 24 below the refrigerant pan 127 provides a water sump 132 which contains the jet pump 39 so that the impeller water and refrigerant and any water vapors purged from the steam condenser 16 are injected into the sump 132 and sump water is withdrawn from the sump through a pump supply line 133 so that the sump water is recirculated through the sump. During normal cooling operation of the system, the sump is maintained at least F. above the temperature of the refrigerant chamber, so that refrigerant in the sum-p is a vapor which passes upwardly about the left end of the refrigerant pan 127 and into the refrigerant chamber 129 from which it is withdrawn through the suction line 121. Water in the refrigerant chamber 129 collects on top of the liquid refrigerant in the pan 127. The chilled water tube bundle 128 is spaced inwardly from the left end wall of the pan to form a relatively quiet area of liquid refrigerant upon which any water in the pan collects in a relatively quiet pool and flows through a suitable weir or port 134 in the end of the pan and into the sump 132. Thus, means is provided for separating refrigerant fluid and power fluid, and for returning these fluids for reuse in the system.

To summarize the operation of the system, if the chilled water temperature drops, indicating a reduced cooling requirement, the modulating refrigerant valve 35 in the refrigerant line 34' to the steam condenser 16 is opened additionally to permit more refrigerant to enter the steam condenser for blanketing the first condensing hundle 34 to reduce the steam condensing capacity and increase steam condenser pressure and the turbine discharge pressure, thus slowing the turbocompresser and causing the compresser 20 to deliver a smaller quantity of refrigerant to the cooler 24, thereby reducing the cooling capacity of the system and increasing the temperature of the leaving chilled water. The pressure and temperature of the steam in the condenser are increased, thus increasing the heating capacity of the second tube bundle 41. Should the chilled water temperature rise, indicating a rise in the cooling requirement, the refrigerant valve 35 is closed sufficiently and less refrigerant is injected into the steam condenser so that the quantity of refrigerant vapor effectively blanketing the first condensing bundle 34 is reduced as the constant rate purge withdraws refrigerant from the steam condenser, thus increasing the cooling capacity and reducing the heating capacity of the system. If desired, suitable guide vanes may be provided on the compressor to improve efficiency somewhat, as is understood in the art.

The following chart indicates various cooling operation conditions throughout the system.

Cooling Capacity 100% 50% 0% Entering Condensing Water, 85 65 85 65 Lv. Chilled Water, F- 44 43 42 41.5 40. 5 40 Cooler:

F 36 35 34 33 32. 5 32 P.s.i.a 19.7 19.2 18.7 18.2 18 17.7 Steam Condenser:

105 85 95 75 86 66 P.s.i.a 7O 51 60 43 62 36 Ref. Leaving Subeooler,

The invention provides a low first cost installation over a wide range of capacities, and small leaks will not render the machine completely inoperative. The machine is completely and truly airtight and routine service requirements are virtually nonexistent, for example, the machine does not require periodic additions of capacity restorer, nor are alkalinity checks required as with most absorption machines.

In the present system, the boiler need never be descaled since no make-up water need be added to the machine. By simple changeover in the turbocompressor, a high steam pressure machine can easily be converted into a low pressure machine, in case operator license requirement becomes important. High partial load efiiciency may be obtained by directly modulating boiler input and by the use of refrigerant compressor inlet guide vanes.

Because the steam condenser condensing rate is regulated by blanketing, control of entering condensing water temperatures and flow rate is unnecessary, so that lower average condensing water temperatures may be utilized for greatly reducing operating costs and effectively preventing scaling. Furthermore, the system completely eliminates condensing or absorbent condensing water bypass lines and valves as are used on most absorption machines and also eliminates the need for sensitive condensing water flow adjustment.

While a preferred embodiment of the invention has been described and illustrated, it will be understood that the invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

1. A method of operating a heating system including a steam condenser, comprising the steps of, passing steam into the steam condenser, removing heat from the steam in the steam condenser to heat a load imposed on the system, passing a noncondensible vapor into the steam condenser to reduce the Condensing capacity thereof and increase the pressure and steam temperature in the steam condenser, thereby increasing the heating capacity of the system, and regulating the quantity of said noncondensible vapor in the steam condenser in response to load imposed on the system, thereby regulating the heating capacity of the system.

2. A method of operating a heating system wherein a steam condenser has a first portion for condensing steam and a second portion for condensing steam and supplying heat to a load comprising the steps of passing steam into said steam condenser, introducing into said steam condenser a fluid which is a noncondensible vapor therein during normal operation of the system, directing said vapor into blanketing association with said first portion to suppress at least a portion of the steam condensing capacity thereof while maintaining said second portion effectively free of said vapor to permit substantially maximum heating of said second portion by said steam, withdrawing from said steam condenser at a substantially constant rate the noncondensible vapor and water vapor carried therewith, and regulating the quantity of said vapor in said steam condenser effective to blanket said first portion thereby varying the steam condensing capacity of said first portion to vary the heating capacity of said second portion inversely of the condensing capacity of said first portion.

3. A method of operating a heating system wherein a steam condenser has a first portion for condensing steam and a second portion for condensing steam and supplying heat to a load comprising the steps of passing steam into said condenser, introducing into said steam condenser a fluid which is a noncondensible vapor within the condenser, directing said vapor into blanketing association with at least a portion of said first portion to suppress the steam condensing capacity thereof while maintaining said second portion eflectively free of said vapor to permit substantially maximum heating of said second portion by said steam, withdrawing from said steam condenser at a substantially constant rate said noncondensible vapor and water vapor carried therewith, regulating the rate of passing said noncondensible vapor into said steam condenser thereby varying the steam condensing capacity of said first portion to vary the condenser pressure and the heating capacity of said second portion inversely of the condensing capacity of said first portion, separating the vapors withdrawn from said steam condenser, and returning the separated fluids for reuse in said steam condenser.

4. In a steam condensing system, the combination of a heat exchanger for steam to be condensed, first means within said heat exchanger for condensing said steam and rejecting the heat involved therein, second means within said heat exchanger to condense said steam and conserve the heat involved therein for supply to a load to be heated, means for passing steam into said heat exchanger, means for passing into said heat exchanger a fluid which is noncondensible vapor at normal operating conditions within said heat exchanger, and means for blanketing said first means with said fluid to suppress the condensing capacity thereof and for maintaining said second means relatively free of said fluid to provide substantially maximum heating of said second means, and means for withdrawing from said heat exchanger at a substantially constant rate the noncondensible vapor and water vapor carried therein.

5. The system of claim 4, and means for regulating the quantity of said fluid effective for blanketing said first means and thereby regulating the heat output of said second means.

6. In a steam condensing system, the combination of a steam condenser, first means in said condenser for condensing steam, second means in said condenser for condensing steam and to be heated thereby for heating a load, divider means between said first means and said second means dividing said enclosing means into a condensate section and another section, respectively, and providing a limited area of communication between said sections, means for passing steam into the other section, means for the removal of steam condensate from said condensate section, and means to control the steam condensing capacity of said first means including means for passing into said condensate section a fluid which is noncondensible vapor in said condenser, means for withdrawing said fluid from said condensate section, and means for regulating the quantity of said fluid effective to blanket said first means to control the condensing rate and thereby the temperature of said steam and the heat output of said second means.

7. In a steam condensing system, the combination of a steam condenser shell for receiving steam to be condensed, first condensing tubes in a lower portion of said shell for condensing said steam and rejecting the heat involved therein, second condensing tubes in an upper portion of said shell for condensing said steam and conserving the heat involved therein for supply to a load to be heated, a baffle between said first condensing tubes and said second condensing tubes dividing said shell into a lower steam condensate section and an upper section, respectively, and providing a limited area of communication between said sections proximate an end of said shell, means for injecting steam into said upper section, means for removing steam condensate from said lower condensate section, and means for directing a fluid which is a noncondensible vapor in said shell into blanketing association with said first condensing tubes in said lower section to control the steam condensing capacity of said first condensing tubes and directing said refrigerant away from said upper section so that said second condensing tubes are eflectively free of said vapor to provide substantially maximum heating of said second condensing tubes and including means for introducing said fluid into said limited area, means within a portion of said condensate section remote from said area for withdrawing said vapor from said shell at a substantially constant rate, and control means for regulating the quantity of said refrigerant vapor passed into said shell, thereby controlling the condensing rate and thereby the temperature of said steam and the heat output of said second condensing tubes.

References Cited UNITED STATES PATENTS 447,396 3/ 1891 Worthington 101 FOREIGN PATENTS 950,517 2/1964 Great Britain.

975,590 11/1964 Great Britain.

ROBERT A. OLEARY, Primary Examiner.

CHARLES SUKALO, Examiner. 

